use XML::Composer;

    my $xml = XML::Composer->new({
        # tag         method
        'ns:foo'  => 'foo',
        'bar'     => 'bar',
        'ns2:baz' => 'baz',
    });
    $xml->Decl; # add declaration (optional)
    $xml->PI('xml-stylesheet', {type => 'text/xsl', href="$xslt_url"});
    $xml->foo(
        { id => 3, 'xmlns:ns2' => $url},
        $xml->bar('silly'),
        $xml->Comment('this is a > comment'),
        $xml->Raw('<bad tag>');
        $xml->baz({'asdf:some_attr' => 'value'}, 'whee!'),
    );
    print $xml->Out;
    if ($xml->Validate) { # false for above example
    }
    __END__
    <?xml version="1.0">
    <?xml-stylesheet type="text/xsl" href="$xslt_url"?>
    <ns:foo id="3" xmlns:ns2="$url">
      <bar>silly</bar>
      <!-- this is a &gt; comment -->
      <bad tag>
      <ns2:baz asdf:some_attr="value">whee!</ns2:baz>
    </ns:foo>